Информация о пользователе

Привет, Гость! Войдите или зарегистрируйтесь.

Ainu DNA

Сообщений 1 страница 4 из 4


Michael F. Hammer, Tatiana M. Karafet, Hwayong Park, Keiichi Omoto, Shinji Harihara, Mark Stoneking, Satoshi Horai
Dual origins of the Japanese: common ground for hunter-gatherer and farmer Y chromosomes

Historic Japanese culture evolved from at least two distinct migrations that originated on the Asian continent. Hunter-gatherers arrived before land bridges were submerged after the last glacial maximum (>12,000 years ago) and gave rise to the Jomon culture, and the Yayoi migration brought wet rice agriculture from Korea beginning approx2,300 years ago. A set of 81 Y chromosome single nucleotide polymorphisms (SNPs) was used to trace the origins of Paleolithic and Neolithic components of the Japanese paternal gene pool, and to determine the relative contribution of Jomon and Yayoi Y chromosome lineages to modern Japanese. Our global sample consisted of >2,500 males from 39 Asian populations, including six populations sampled from across the Japanese archipelago. Japanese populations were characterized by the presence of two major (D and O) and two minor (C and N) clades of Y chromosomes, each with several sub-lineages. Haplogroup D chromosomes were present at 34.7% and were distributed in a U-shaped pattern with the highest frequency in the northern Ainu and southern Ryukyuans. In contrast, haplogroup O lineages (51.8%) were distributed in an inverted U-shaped pattern with a maximum frequency on Kyushu. Coalescent analyses of Y chromosome short tandem repeat diversity indicated that haplogroups D and C began their expansions in Japan approx20,000 and approx12,000 years ago, respectively, while haplogroup O-47z began its expansion only approx4,000 years ago. We infer that these patterns result from separate and distinct genetic contributions from both the Jomon and the Yayoi cultures to modern Japanese, with varying levels of admixture between these two populations across the archipelago. The results also support the hypothesis of a Central Asian origin of Jomonese ancestors, and a Southeast Asian origin of the ancestors of the Yayoi, contra previous models based on morphological and genetic evidence.



Genetic origins of the Ainu inferred from combined DNA analyses of maternal and paternal lineages

Atsushi Tajima, Masanori Hayami, Katsushi Tokunaga, Takeo Juji, Masafumi Matsuo, Sangkot Marzuki, Keiichi Omoto and Satoshi Horai

The Ainu, a minority ethnic group from the northernmost island of Japan, was investigated for DNA polymorphisms both from maternal (mitochondrial DNA) and paternal (Y chromosome) lineages extensively. Other Asian populations inhabiting North, East, and Southeast Asia were also examined for detailed phylogeographic analyses at the mtDNA sequence type as well as Y-haplogroup levels. The maternal and paternal gene pools of the Ainu contained 25 mtDNA sequence types and three Y-haplogroups, respectively. Eleven of the 25 mtDNA sequence types were unique to the Ainu and accounted for over 50% of the population, whereas 14 were widely distributed among other Asian populations. Of the 14 shared types, the most frequently shared type was found in common among the Ainu, Nivkhi in northern Sakhalin, and Koryaks in the Kamchatka Peninsula. Moreover, analysis of genetic distances calculated from the mtDNA data revealed that the Ainu seemed to be related to both the Nivkhi and other Japanese populations (such as mainland Japanese and Okinawans) at the population level. On the paternal side, the vast majority (87.5%) of the Ainu exhibited the Asian-specific YAP+ lineages (Y-haplogroups D-M55* and D-M125), which were distributed only in the Japanese Archipelago in this analysis. On the other hand, the Ainu exhibited no other Y-haplogroups (C-M8, O-M175*, and O-M122*) common in mainland Japanese and Okinawans. It is noteworthy that the rest of the Ainu gene pool was occupied by the paternal lineage (Y-haplogroup C-M217*) from North Asia including Sakhalin. Thus, the present findings suggest that the Ainu retain a certain degree of their own genetic uniqueness, while having higher genetic affinities with other regional populations in Japan and the Nivkhi among Asian populations. … 0432a.html





The continental origins of Japanese Y haplogroups
Given that we have identified putative Y chromosome
markers of Jomon (or pre-Jomon) and Yayoi migrations,
can we trace the origins of these lineages before
they entered Japan? We infer that the Japanese have at
least two lineages (D-P37.1 and C-M8) that descend
from Paleolithic founders. Evidence from SNPs and
STRs (Table 2) suggests that both lineages have great
genealogical depth. In the case of haplogroup D, a
striking number of point mutations have accumulated
on this Japanese lineage (Fig. 2). The divergence of the
Japanese D lineage implies a very early period of dispersal
into the Japanese archipelago followed by a long
period of isolation from populations on the mainland.
There is only one other lineage that exhibits more
mutations along an internal branch on the Y chromosome
haplogroup tree (YCC 2002; Jobling and Tyler-
Smith 2003). This branch, A2, is found among the
Khoisan of Namibia, a population that also may have
been isolated for a very long period of time (Hammer
et al. 2001; Wilder et al. 2004).
The highest frequency of continental D lineages is
found in central Asia (Fig. 2), especially in Tibet
(50.4%). Evidence for shared ancestry between Tibetans
and Japanese is seen in the MDS plot (Fig. 3). We
hypothesize that the area between Tibet and the Altai
Mountains in northwestern China is the primary
candidate region for the geographic source of Paleolithic
Japanese founding Y chromosomes. Although Tibetans
and people from the Altai have D lineages that are differentiated
from those in Japan, there are still ‘‘ancestral’’
chromosomes that are not marked by any known
mutations on the D lineage in Tibet and the Altai
(Fig. 2). Historical records suggest that Tibetan populations
were derived from ancient tribes of northwestern
China that subsequently moved to the south and admixed
with southern natives in the last 3,000 years (Ruofu
and Yip 1993; Cavalli-Sforza et al. 1994; Wen et al.
2004). The survival of ancient lineages within haplogroup
D in Tibetans and Japanese may well reflect long periods
of isolation for both groups. Interestingly, a Y-SNP
survey of Andaman Islanders found a very high frequency
of haplogroup D-M174* chromosomes in this
isolated population that likely descends from Paleolithic
Asian ancestors (Thangaraj et al. 2003). Recent expansions
and population replacements in Asia, perhaps
associated with the spread of agriculture, may have led to
the near extinction of haplogroup D in other Asian


Создать форум. Создать магазин